hitchner



(No Model.) 4 Sheets-Sheet 1.

o. W. HITOHNER.

AUTOMATIC BAKE OVEN.

No 564,074. P tented July 14-, 1896.

-(No Model.) 4 SheetS Sheet 2. U. W. HITOHNER.

' AUTOMATIC BAKE OVEN.

No. 564,074, Patented July 14, 1896.

v jzwzzzoif I Za rferlfllitcfimr No Model!) 4 ShetsSheet 3. G.W.-HITOHNER.

AUTOMATIC BAKE OVEN. No. 564,074; Patented Jul yy, 1896i UNITED STATESPATENT OFFICE.

CHESTER WV. HITCHNER, OF SORANTON, PENNSYLVANIA, ASSIGNOR TO CALVIN WPARSONS, OF SAME PLACE.

I AUTOMATIC SPECIFICATION forming part of Letters Patent No. 564,074,dated July 14, 1896. Application filed September 11, 1895. Serial No.562,161. I (No model.)

To aZZ whom it may concern.-

Be it known that I, CHESTER W. HITCHNER, a citizen of the United States,residing at Scranton, in the county of Lackawanna and State ofPennsylvania, have invented new and useful Improvements in AutomaticBake- Ovens, of which the following is a specification.

My invention relates to an automatic oven especially adapted to thebaking of crackers and similar goods, and has for its objects to securea very large capacity with much less floor-space than is ordinarilyrequired; to improve the construction of the furnace and oven so thatthe goods will not be exposed to the direct radiation of heat from thefurnacevfire; to provide means for regulating the distribution of heatthroughout the bakingchamber; to provide improved mechanismforautomatically controlling the movements of a series of travelingbake-pans or shelves; to provide for an automatic discharge of the bakedor finished goods; to prevent the escape of hot gases at the doorthrough which an attendant introduces fresh goods, thus greatlyimproving the sanitary conditions of the work, and to generally improvethe construction and operation of this class of ovens.

The invention consists in the features of construction and novelcombinations of parts in an automatic oven, as hereinafter moreparticularly described and claimed.

In the annexed drawings, illustrating the invention, Figure 1 is asectional side elevation of my improved automatic oven. Fig. 2 is avertical transverse section of the same 011 the line 2 2 of Fig. 1. Fig.3 is a horizontal section on the line 3 3 of Fig. 1. Fig. 4 is a similarsection on the line 4 4 of Fig. 2. Fig. 5 is a plan of driving mechanismfor automatically controlling the movements of the bake-pans or shelvesand the automatic discharge of their contents. Fig. 6 is a sideelevation of said automatic driving mechanism. Fig. 7 is an endelevation of the same. Fig. 8 is a side elevation of the automatic oven,parts of the automatic stopping and starting mechanism being in sectionand other parts removed. Fig. 9 is a front elevation of the same.

Referring to the drawings, the numeral 1 designates the walls of avertically-elongated oven-furnace that is so constructed and arranged asto occupy comparatively little floor-space in proportion to the heightand capacity of the baking apparatus. The lower part of the furnace isdivided transversely by a bridge-wall 2, Figs. 1 and 2, between whichand the furnace-front are located the grates 3. There are preferably twogrates, separated longitudinally by awall 4. At the front upper side ofeach grate is the usual door 6, and below this is a door 7,communicating with the ash-pit.

Above the front portion of each grate 3 is a short arch S,eXtended onlypartly rearward. A short distance above the small arches S is a largearch 9,t hat is extended from side to side of the furnace,but not quitefrom front to rear. At the front of the arch 9, above the arches 8, areopenings 10, Figs. 1 and 4C, for the passage of hot air into the oven orbakingchamber 11, located above the main arch. The short arches 8 serveto prevent a direct radiation of heat, through these openings 10, intothe baking-chamber. of the main arch 9 is an opening 12, Figs. 1 and 4,also leading to the baking-chamber, for the passage of hot air thereto.These openings 10 and 12 maybe closed or controlled by means of slidingplates or dampers 13, so that the heat from the fire may be directed tothe front or back of the baking-chamber in any proportion that may bedesired. The heat and products of combustion will fill the wholebaking-chamber when the dampers 13 are opened, and may be allowed toescape into the chimney 14, through openings 15 and 16, controlled bydampers 17, as required. Another opening 18, controlled by a damper 19,is provided below the arch 9 and is to be used as a passage to thechimney 14: when starting the fires and when the dampers 13 are closedfor cooling the oven or for other purposes. I

In the side walls of the baking-chamber 11 are mounted bearings orjournal-boxes 20, Fig. 2, that receive the ends of transverselyarrangedshafts 21 and 22, Fig. 1, on which are secured sprocket wheels 23 nearthe.

ends of said shafts. There are two sprocketwheels on the upper shaft 21and two on the At the rear end lower shaft 22, and the wheels on theseshafts are connected by chains 24,running vertically and parallel witheach other. This arrangement enables the baking-chamber or oven 11 to beextended to a considerable height and gives it a large capacity withgreat economy of floor-space.

The goods to be baked are placed upon shelves or pans and 26, arrangedin pairs, one above another, and suspended between the chains 24, thattravel on the sprocketwheels. These shelves 25 and 26 consist of thinsheetsiron plates, strengthened by suitable frames of angle-iron andconnected in pairs by rigid vertically-arranged bars 27 at the ends ofthe plates or shelves. A horizontally-arranged bar 28 connects theVertical bars 27 at each end of the shelves, and through each pair ofbars 28 is passed a transversely-arranged rod 29, to the ends of whichare connected the chains 24, the horizontal bars 28 being arrangednearer to the upper pan or shelf in each pair, so that the suspendedshelves will maintain a horizontal position. All the shelves in theseries are at equal distances apart.

At a suitable elevation in front of the baking-chamber 11 is a floor orplatform 30 for an attendant to stand upon. Above this floor or platform30 there is provided in the front of the baking-chamber 11 an opening31, through which access is had for loading and unloading thevertically-traveling shelves. There is arranged inside the opening 31and within the chamber 11 an air-lock 32, Fig. 1, consisting of a frontplate 33, a rear plate 34, and side plates 35, the said air-lock beingthus in the form of a rectangular tube or vertical box open at its topand bottom for passage of the traveling shelves. The opening 31 in thefront of the oven may be provided with a flanged casing or framing 36,extended partly into the baking-chamber, and the plate 33 at the frontlower portion of the air-lock is preferably extended to and connectedwith this casing. The larger part of the opening 31 is separated fromthe air-lock 32 by a screen or partition 37, extended between the sidesof the casing 36,and preferably constructed from some material that is anon-conductor of heat. Below the screen 37 there is left an opening orpassage-way 38 for use in loading the traveling shelves and which may bedesignated as the loading-door. Above the screen or partition 37 is anopening or passage-way 39, that may be termed the unloading-door,through which the baked contents of the pans or shelves are to beautomatically discharged into any suitable receptacle. (Not shown.)

The baking is accomplished while the goods on the shelves 25 and 26 makea circuit from the loading-door 38, around the oven to theunloading-door 39, once vertically around the oven being ordinarilysufficient. Some kinds of goods will require more time than others forproper baking. For these the speed of the traveling shelves will bereduced, or the shelves may be allowed to make several circuits beforethe goods are discharged; but the apparatus as here shown is adjusted toallow the goods to make one circuit only.

It will be observed that the box or air-lock 32 is of such height as toinclose two or more of the shelves at one time. The interior di mensionsof this box or air-lock 32 are just sufficient to permit free passage ofthe series of shelves, one or more of which serve at all times to cutoff communication between the charging 01' loading door 38 and theinterior of the baking-chamber. Thus little or no gas can escape at thecharging-door. The escape of gas at the unloading-door 39 may bedisregarded, as it will not seriously incommode the attendant. It isevident that the air-lock could be extended to prevent escape of gas atthe upper door, but it is deemed unnecessary.

The shelves are arranged at equal distances apart, and, being suspendedin the manner described, they will readily maintain a horizontalposition throughout all parts of the circuit and during the operationsof loading and unloading.

By suspending the shelves in pairs, as shown, they may be hung andoperated much closer together than if they were hung singly.

In practice it is found that the space required between successiveshelves to enable them to clear each other properly when passing aroundthe sprocket-wheels (the width of the shelves being the same in bothcases) is about one-half more when they are hung singly than when theyare hung in pairs, as shown. The height of the baking-chamber requiredfor a given capacity is thus greatly reduced.

For the purpose of removing the finished goods from the oven each shelf25 and 26 is provided with a scraper 40, Fig. 3, which is extendedaround the rear side and the two ends of the shelf and is provided withlaterally-extended lugs 41 at its front ends. The scraper 40 thussurrounds three sides of the shelf-top and serves as a rim to retain thegoods in place. As the shelves successively descend into position at thedischarging-door 39 the lugs 41 on the scraper 40 enter gooves 42 in theends of bars 43, adapted to slide on guides 44, and which bars 43 arepivotally connected to levers 45, keyed to a rock-shaft 46,-mounted inbearings 47 at the front of the oven. This rock-shaft 46 is vibrated bymechanism hereinafter described, and thus at the proper time the leversare swung outward, as shown in Fig. 1, thereby dragging the scraper 40off from the shelf, so as to cause it to scrape the finished goodsthrough the door 39 and into a suitable receptacle.

The sprocket-wheels, chains, and shelves are moved intermittently bymechanism that starts and stops automatically, and thedischarging-scraper is actuated by automatically-operating mechanism,while the shelves are at rest.

On the shaft 21 of the upper sprocket-wheels is secured a spur-gear 48,Figs. 2, 8, and 9, located outside the oven. This gear 48 is driven by apinion 49 on a short shaft 50, journaled in suitable bearings on abracket or frame 51, secured to the outside of the oven. On the sameshaft with the pinion 49 is secured a worm-wheel 52, driven from a worm53, mounted upon a sleeve 54, to which a belt-pulley 55 is also secured.The sleeve 54 is supported on a shaft 56, having a beltpulley 57 securedthereon alongside the beltpulley on said sleeve. On the shaft 56 is aworm 58 for driving a worm-wheel 59 on a shaft 60, to which a crank-armor crank-Wheel 61 is also secured. The crank-wheel 61 carries awrist-pin 62, connected by a rod 63 to a lever 64 on the rock-shaft 46,through which the dischargin g-scrapers 40 are automatically actuated.

The worms 53 and 58 ar driven alternately as the belt 65 is shifted fromthe pulley 55 to the pulley 57 and back.

The worm-wheel 52 carries a series of stoppins 66 for engaging anupward-projecting finger or tappet 67 secured to a horizontallyslidingrod 68, for which suitable guide-supports are provided on the frame 51,in which the several parts of the automatic driving mechanism aremounted. On the worm-wh eel 59 is carried astop-pin 69, for engaging adepending finger or tappet 70, secured on the sliding rod 68. Thissliding rod 68 is provided at a suitable point with collars 71, engagingthe bifurcated lower end of an arm 72, Fig. 6, depending from arock-shaft 73, journaled in the frame 51. On the rock-shaft 73 is anupward-extended arm 74, provided at its upper end with a pin 75, engagedin an elongated eye 76, formed in one end of a rod 77, the other end ofwhich is supported by the upper end of a three-armed lever 7 8,fulcrumed at 79, Fig. 6, to the frame 51. To the lower arms of the lever7 8-are attached brakestraps 80 and 81, that are passed partly aroundthe pulleys55 and 57 and may be tightened and adjusted by means of nuts82, Figs. 5 and 7, at the points where said straps are attached to theframe 51. On the end of the rod 77, adjacent to the brake-lever 78, iscarried a belt-shifter 83 for moving the belt 65 from one pulley to theother.

The rock-shaft 73 carries an upward-projecting arm 84, Fig. 7, having onits upper end an inverted-V-shaped cam 85, Fig. 6, engaged by a roller86, mounted on a weighted lever 87, one end of which is fulcrumed at 88,while a weight 89 is mounted on the other end.

The worm-wheels 52 and 59 are rotated in opposite directions, asindicated by the arrows in Fig. 6. The wheel 52 operates to move theshelves of the oven. The wheel 59 drives thecrank-pin 62, which operatesthe mechanism for scraping the finished goods off from the oven-shelves.

While the driving-belt 65 is on the pulley 55, as shown in Fig. 6, theworm 53 will causev rotation of the worm-wheel 52, and one of the pins66 thereon will be carried into engagement with the upward-projectingfinger 67, thereby moving the rod 68 longitudinally. Through thismovement of the rod 68 the arm 72 will be caused to rock the shaft 73and the arms 74 and 84 thereon, the pin will be moved along in the slotor eye 7 6 of the rod 7 7, and the apex of the cam 85 will be broughtdirectly beneath the roller 86 on the weighted lever 87 ,as shown inFig. 6. As the rotation of the wheel 52 is continued, the apex of thecam 85 will pass to one side of the roller 86, and the consequent fallof the weight 89 will immediately forcethe rook-shaft arms to the limitof their movement. The slot or elongated eye 7 6 in the rod 77 permitsthe rock- 'shaft arms to move to mid-stroke without moving thebeltshifter 83 and brake-lever 78, but the movement of the cam 85 andits supporting rook-shaft arm from the center line moves the rod 77 asufficient distance to at once shift the belt 65 onto the other pulley.At the same time the movement of the rod 77 rocks the three-armed lever7 8, and thereby tightens the brake-strap of pulley 55 and loosens thebrake-strap 81 of pulley 57 just as the belt 65 is shifted. The wheel 52and its actuating-worm 53 thus come to rest immediately as soon as thebelt 65 is shifted from the pulley 55 to the pulley 57, and the amountof movement thus given to the wheels 52, 49, and 48 is sufficient tobring the shelf into position before the discharging-door 39 inreadiness for unloading.

As soon as the driving-belt 65 is shifted onto the pulley 57 the shaft56 and worm 58 will be rotated, thereby causing a rotation of theworm-wheel 59 in the direction of the arrow shown in Fig. 6, while theworm-wheel 52 remains at rest. By the rotation of the worm-wheel 59,shaft 60, and crank 61 thereon the wrist-pin 62 will be caused to movethe rod 63, lever 64, and rock-shaft 46in such direction that the levers45 011 said rock-shaft will draw on the bars 43, Figs. 1 and 3, so as todrag the scraper 40 outward and thereby automatically discharge thefinished goods from off the shelf at the unloading-door of the oven. Thecontinued rotation of the wheel 59, crank 61, and pin 62 will cause arocking of the shaft 46 in reverse direction and thereby return thescraper 40 to its shelf. The stop-pin 69 on the worm-wheel 59 will nowengage the depending finger 70, Fig. 6, the rod 68 will be moved back,thereby rocking the shaft 73 and attached arms in a reverse direction,and the roller 86 will drop down the opposite side of the cam andthereby cause the rod 77 and belt-shifter 83 to promptly shift the belt65 from the pulley 57 to the pulley 55, the lever 78 at the same timeslackening the brake-strap 80 and tightening the brake-strap 81,whereupon the wheel 59 will be stopped and the wheel 52 caused to resumeits operation and set the oven-shelves in motion. Thus the wheel 52,

IIO

through which the oven-shelves are actuated, revolves only until the camreaches midstroke, when the Weighted lever 87 promptly acts to cause thebelt to be shifted onto the pulley 57 and thereby starts the worm 58 andworm-wheel 59 to revolving. The motion of the wheel 59 continues untilthe cam 85 and weighted lever 87 can shift the belt back onto the pulley55. \V hen the belt shifter is moved, the brake-strap on one pulley isat the same time slackened and the strap on the other pulley istightened, thus bringing the previously-movin g parts promptly to rest.

During the intervals that the oven-shelves are at rest the automaticdischarging mechanism is at work removing finished goods from the shelfat the unloading-door 39, and the attendant is occupied in placing freshgoods upon a shelf at the charging or loading door 38. The proportion oftime allowed for these operations before the oven-shelves are againautomatically set in motion. is determined by the relative number ofteeth in the wheel 59 and those included between the pins 66 on thewheel 52.

It is not essential that the gears 48 and 49 be employed. The wheel 52may take the place of these gears by mounting said Wheel 52 on the shaft21 of the upperpair of sprocketwheels, but the arrangement shown ispreferred because it permits the automatic driving mechanism to bemounted altogether in an independent frame 51, which permits adjustmentto compensate for any warping or distortion of the brickwork by heat.

It will be seen that in the operation of the oven the attendant has onlyto place fresh goods upon the shelves, the removal of the finished goodsand the starting and stopping of the shelves being accomplishedautomatically. The labor of one man is thus saved and a higher and moreuniform speed is made practicable.

It will be obvious that the air-lock the construction of the furnace andfire-arches, the suspension of the shelves in pairs, the provision of ascraper on each shelf, serving also as a rim, and the automaticmechanism for moving the shelves and working the scrapers may, severallyor all, be applied to advantage in any form of oven. in which theshelves or bake-pans are designed to have a traveling movement.

What I claim as my invention is- 1. In an even, a series of shelvesrigidly connected in pairs, and suspended at equal distances between andfrom endless movable chains, substantially as described.

2. In an oven, a series of shelves connected in pairs by rigid frames,in combination with transversely-arranged rods extended through saidframes nearthe under side of the upper shelf in each pair, and endlessmovable chains to which the ends of said rods are attached and wherebythe shelves are suspended between said chains and maintained inhorizontal position, substantially as described.

3. In an oven, the combination with endless traveling chains, and aseries of shelves, of vertical frame-bars rigidly connecting saidshelves in pairs, horizontal frame-bars connectin g each pair ofvertical bars and arranged nearest the upper shelf in each pair, andtransversely-arranged rods j ournaled to said horizontal bars, andattached to the endless chains, to suspend the shelves between saidchains, substantially as described.

4:. In an even having a charging-door, the combination with said doorand with a series of vertically-traveling shelves located in the even,of an air-lock communicating With said door and through which theshelves are arranged to pass, the said shelves being adapted to cut offdirect communication between the oven and said door to prevent theescape of gases, substantially as described.

5. In an oven, the combination with a series of vertically-movableshelves, and a charging-door and an unloading'door located one above theother, of an air-lock located in the oven adjacent to and comm unieatingwith the charging-door and through which air-lock the shelves arearranged to pass, the said air-lock and one or more shelves thereinbeing adapted to cutoif communication between the oven and thecharging-door and prevent the escape of gas, substantially as described.

(i. In an oven, the combination with a series of traveling shelves, of ascraper carried on each shelf, and automatic mechanism adapted to engage each scraper in succession and cause it to discharge or remove thecontents of the shelf.

7. In an oven, the combination with a series of traveling shelves andscrapers carried on said shelves and partly surrounding the same toretain their contents, of automatic mechanism adapted to engage thescrapers in succession and cause them to discharge or remove the shelfcontents, substantially as described.

S. In an oven, the combination with a series of vertically-travelingshelves, and scrapers carried on said shelves, and each provided withlugs, of a pair of sliding bars or arms having vertical grooves toengage the lugs of said scrapers in succession, a rock-shafthavinglever-arms connected to said sliding bars, and automatic mechanism foroperating said rock-shaft to actuate and return the scraper,substantially as described.

9. In an oven, the combination with a series of traveling shelvessuspended from and between endless vertically movable chains,sprocket-wheels on which said chains are mounted, and scrapers carriedon said shelves, of a worm wheel for driving the shaft of the uppersprocket-wheels, a sleeve having mounted thereon a worm engaging andadapted to drive said worm-wheel, a belt-pulley on said sleeve, a shafton which said sleeve is loosely mounted, a belt-pulley and a worm onsaid shaft, a worm-wheel engaged with and adapted to be driven by saidlast-named worm, a crank on the same shaft with said last-namedworm-wheel, mechanism adapted to successively connect said crank withthe scrapers on the oven-shelves, a sliding rod provided with projectingfingers, stop-pins carried by the Worm-wheels to engage said lingers andmove the sliding rod alternately in opposite directions, a belt-shifter,a brakelever, and mechanism connecting said sliding rod with thebelt-shifter and brake-lever to shift a driving-belt from one pulley tothe other and alternately actuate the traveling shelves and scrapingmechanism, substantially as described.

10. In an oven, the combination with a series of shelves, endlessmovable chains from which said shelves are suspended, and scrapingmechanism for discharging the contents of the shelves, of drivingmechanism for alternately actuating the shelf-carrying chains and thescraping mechanism, and means for automatically starting and stoppingthe said driving mechanism, substantially as described.

11. In an oven, the combination with series of shelves, and endlessvertically-movable chains from which said shelves are suspended, ofscrapers carried on said shelves and provided with lugs 41, therock-shaft 46 having arms and 64, the bars 43 connected to said arms 45and provided with grooves 42 to engage lugs 41 on the scrapers, theshaft having thereon a crank 61 provided with wrist-pin 62, the rod 63connecting the pin 62 and rock-shaft arm 64, gearing for intermittentlyactuating the shaft 60 and the chains that carry the oven-shelves, andmeans for alternately driving the said shaft and the shelfcarryingchains, substantially as described.

12. In an oven, the combination with the series of traveling shelves andtheir scraping mechanism, of the Worm-Wheel 52 provided with pins 66,the worm-wheel 59 provided with a pin 69, gearing for connecting theworm-wheel 52 with the shelf-carrying devices, a crank 61 mounted on thesame shaft with the worm-Wheel 59 and connected with the scrapermechanism; intermittently-actuated WOI'IHS 53 and 58 engaged with andadapted to alternately drive the worm-Wheels 52 and 59, a sliding rod 68having fingers 67 and 7 O to be engaged by the pins on the said wheels52 and 59, belt-pulleys 55 and 57 connected to the worms 53 and 58, thebrakelever 78 having brake-straps 80 and 81 bearing upon said pulleys,the rock-shaft 7 3 having arms 72, 74 and 84, one of said arms be ingconnected with the sliding rod 68, a rod 77 connected with thebrake-lever 78 and with apin on the rock-shaft arm 7 4, the belt-shifter83 carried by said rod 77, a cam 85 on the rock-shaft arm 84, and theweighted lever 87 having a roller 86 engaged with said cam,substantially as described.

13. In an oven, the combination with the intermittently-travelingshelves and their scrapingmechanism, and the alternately-operatedgearing for actuating the shelves and scrapers, of the belt-shifter 83,the rod 77 having an eye 76, the rock-shaft 73 provided with arms 74 and84, a pin 75 carried on the arm 74 and engaged in the eye 76, the cam 85on the arm 84 the lever 87 provided with roller 86 and weight 89, andmeans for oscillating the rock-shaft 73 from the drivinggears,substantially as described.

14. In an oven, the combination with the baking-chamber and the grate,of the arch 9 having openings 10 and 12 at its front and rear ends,respectively, the dampers 13 for controlling said openings, and thearches or shields 8 beneath the front openings, substantially asdescribed.

In testimony whereof I have hereunto set my hand in presence of twosubscribing witnesses.

CHESTER YV. HITOHNER.

lVitnesses:

WM. F. BOYLE, OHAs. E. OLVES.

